Ice-making tray

ABSTRACT

An ice-making tray includes an attachment part; a metal tray part; a heater for heating the tray part; and at least one heater guide. The tray part is formed as a separate body from the attachment part. The heater guide is made of metal and comes into contact with the heater and the tray part. The heater guide is attached to the attachment part to hold the heater, and transmits heat of the heater to the tray part.

TECHNICAL FIELD

The present invention relates to an ice-making tray, arranged in a freezing compartment of a household refrigerator or the like, for making ice by supplying water and cooling the same.

BACKGROUND ART

An ice-making tray arranged in a freezing component of a fridge-freezer is entirely formed by aluminum die cast molding, for example. Such the ice-making tray is disclosed in Patent Document 1. A conventional ice-making tray will be described below with reference to the drawings. FIG. 8 is a perspective view of an ice-making tray used in a conventional fridge-freezer. FIG. 9 is a cross sectional view of the ice-making tray shown in FIG. 8.

Ice-making tray 1 is formed by die cast molding an aluminum alloy, which is a metal having high thermal conductivity. Ice-making tray 1 includes plural cells 2 for temporarily retaining water, and attachment part 5 for fixing to the wall face of a refrigerator or the like, with screws. Cell 2 and attachment part 5 are integrally molded. Adjacent cells 2 are connected with groove 3. As shown in FIG. 9, heater 4 is closely attached and fixed to the lower surface of ice-making tray 1 with caulking, screw, and the like.

The operation of ice-making tray 1 configured as above will be described below. When water is supplied to ice-making tray 1, water spreads entirely through groove 3, so that all cells 2 are filled with water. One cell 2 can contain about 15 ml of water, and thus about 105 ml of water is supplied to ice-making tray 1 with seven cells 2.

The water supplied to ice-making tray 1 radiates heat and the temperature thereof gradually lowers by heat conduction from the water surface, and heat conduction or radiation from the wall surface of ice-making tray 1, and eventually freezes thereby making ice. When current flows to heater 4, the ice melts at the portion contacting ice-making tray 1, and the formed ice is discharged from ice-making tray 1 by an ice discharge nail (not shown).

As described above, attachment part 5 to the refrigerator or the like, and sites etc. for fixing heater 4 are arranged in ice-making tray 1 formed by aluminum die cast molding. The thickness of ice-making tray 1 is thus uneven.

Heater 4 is, for example, caulking fixed to ice-making tray 1 at four locations. When current flows to heater 4 after ice is made in ice-making tray 1, heat is transmitted from a caulked part to the ice. However, a caulking state is not necessarily always the same.

The transmission of heat to all cells 2 of ice-making tray 1 thus becomes non-uniform due to unevenness in the thickness of ice-making tray 1 and unevenness in caulking. The ice thus cannot be reliably separated unless ice-making tray 1 is heated to more than necessary. That is, the current-flowing time to heater 4 needs to be long. The temperature of cell 2 differs depending on the location, and the time from supply of water to ice-making tray 1 to formation of ice or the next ice-making cycle becomes long.

Patent Document 1: Unexamined Japanese Patent Publication No. 2001-272146

DISCLOSURE OF THE INVENTION

The present invention relates to an ice-making tray capable of shortening the heater current-flowing time by evening the transmission of heat from the heater, and enabling the temperature, after the termination of current flow to the heater, to easily lower by reducing the temperature difference of each part to speed up the next ice-making cycle. The ice-making tray of the present invention includes an attachment part; a tray part made of metal; a heater for heating the tray part; and at least one heater guide. The tray part is formed as a separate body from the attachment part. The heater guide is made of metal and comes into contact with the heater and the tray part. The heater guide is attached to the attachment part and holds the heater, and transmits the heat of the heater to the tray part.

In such configuration, the tray part can be manufactured by press work, and the thickness becomes substantially even. When the current flows to heater, the heat is transmitted to the tray part from a site where the heater is closely attached to the tray part by the heater guide and a site where the heater guide and the tray part are closely attached. Thus heat is transmitted from a great number of sites. Taking also into consideration that the thickness of the tray part is even, the heat is evenly transmitted to the tray part in a short period of time. The speed of the next ice-making cycle becomes faster. Thus, by enhancing the heat transmission efficiency from the heater to the tray part by the heater guide, the heater current flow can be reduced, and the ice-making cycle can be shortened.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an ice-making tray according to an embodiment of the present invention.

FIG. 2 is a perspective view of the ice-making tray shown in FIG. 1 seen from below.

FIG. 3 is a perspective view of an automatic ice-making device including the ice-making tray shown in FIG. 1.

FIG. 4 is a perspective view of a heater guide in the ice-making tray shown in FIG. 1.

FIG. 5 is a cross sectional view of the ice-making tray shown in FIG. 1.

FIG. 6 is a perspective view of another ice-making tray according to the embodiment of the present invention seen from below.

FIG. 7 is a perspective view of still another ice-making tray according to the embodiment of the present invention seen from below.

FIG. 8 is a perspective view of a conventional ice-making tray.

FIG. 9 is a cross sectional view of the ice-making tray shown in FIG. 8.

REFERENCE MARKS IN THE DRAWINGS

-   11 Ice-making tray -   12 Attachment part -   12A Fixing portion -   12B Water pouring port -   13 Tray part -   13A Bottom surface -   13B Cell -   13C Groove -   13D Partition plate -   14 Heater -   15, 15K, 15L, 15M Heater guide -   15A Raised portion -   15B Fin -   16 Screw -   17 Ice-making mechanism

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Embodiments of the present invention will be described below with reference to the drawings. It should be noted that the present invention is not limited to these embodiments.

FIG. 1 is a perspective view of an ice-making tray according to an embodiment of the present invention, FIG. 2 is a perspective view of the ice-making tray seen from below, and FIG. 3 is a perspective view of an automatic ice-making device including the ice-making tray. FIG. 4 is a perspective view of a heater guide in the ice-making tray, and FIG. 5 is a cross sectional view of the ice-making tray. Ice-making tray 11 includes attachment part 12 for fixing ice-making tray 11 to a refrigerator or the like, metal tray part 13 formed as a separate body from attachment part 12, heater 14, and heater guide 15.

Tray part 13 has bottom surface 13A of semicircular cross section, and, for example, six partition plates 13D coupled to bottom surface 13A. Partition plate 13D divides the interior of tray part 13 into seven cells 13B for temporarily retaining water. Groove 13C enabling water to move in and move out between cells 13B is formed in partition plate 13D. Tray part 13 is formed by press drawing work, and partition plate 13D is formed by press extracting work.

Attachment part 12 includes fixing portion 12A for fixing to the wall surface of the refrigerator or the like, with screws or the like, and water pouring port 12B for pouring water from a water supply valve (not shown).

U-shaped heater 14 for heating tray part 13 is arranged at the lower surface of tray part 13. Heater 14 is held by heater guide 15, and is fixed to attachment part 12 by screw 16 so as to closely contact tray part 13. That is, heater guide 15 comes into contact with heater 14 and tray part 13, and is attached to attachment part 12 to hold heater 14.

The material constituting tray part 13 and heater guide 15 is metal having high thermal conductivity, and is constituted, for example, with aluminum or an alloy thereof. Attachment part 12 is made of resin such as ABS (Acrylonitrile Butadiene Styrene) resin.

As shown in FIG. 3, the automatic ice-making device is configured by ice-making tray 11, an ice discharge mechanism, and ice-making mechanism 17 including a temperature sensor, an ice storage detection mechanism, and a control circuit of tray part 13.

The operation and the effect of the ice-making tray configured as above will be described below. When water is supplied from a water supply valve (not shown) to cell 13B adjacent to water pouring port 12B through water pouring port 12B, water spreads to all cells 13B through groove 13C. In the present embodiment, about 105 ml of water is supplied so that about 15 ml of water is filled in one cell 13B.

The water supplied to cell 13B is cooled by heat conduction from tray part 13, and ice-making is completed in a short period of time. After ice-making is completed, current flows to heater 14, tray part 13 is warmed, and the ice is separated from tray part 13. Thereafter, the ice of tray part 13 is discharged by an ice discharge nail (not shown).

Ice-making tray 11 is configured by attachment part 12 and tray part 13 formed as a separate body from attachment part 12. The shape is thus simplified. Tray part 13 can be molded by press working, and can be thinned and evened in thickness by die cast molding, so that the material cost is reduced and the durability of the die is enhanced.

When current flows to heater 14 after the ice is made in tray part 13, the heat of heater 14 transmits to the ice through tray part 13. This heat transmits to tray part 13 from a site where heater 14 is closely attached to tray part 13 by heater guide 15, and a site where heater guide 15 is closely attached to tray part 13. Since the thickness of tray part 13 is substantially even, the heat is uniformly transmitted to tray part 13 in a short period of time. An appropriate temperature detection becomes possible irrespective of the position on tray part 13 of the temperature sensor in ice-making mechanism 17. Thus, an appropriate control for melting the ice at minimum can be performed. That is, the current-flowing time of heater 14 can be reduced and power consumption of heater 14 can be reduced.

Press worked tray part 13 is not suitable for fixing heater 14 by caulking. Thus, the method of fixing heater guide 15 to attachment part 12 by screw 16 is suitable for tray part 13.

The portion contacting heater 14 of heater guide 15 preferably has a circular arc shape so as to lie along the shape of heater 14. The close attachment between heater 14 and heater guide 15 is ensured by this shape. Thus, the heat is more easily transmitted to tray part 13 from the site closely attached to tray part 13 of heater 14 and the site closely attached to tray part 13 of heater guide 15. That is, heat conduction efficiency from heater 14 to tray part 13 is more enhanced.

Since tray part 13 is thinned and evened in thickness, the temperature of the entire tray part 13 lowers compared to the case where attachment part 12 and tray part 13 are configured with an integral die cast molded article. Thus, the time for lowering the temperature of tray part 13 after current-flow to heater 14 is terminated becomes faster, and the time from supply of water to tray part 13 to formation of ice or the next ice-making cycle can be reduced.

As shown in FIGS. 4 and 5, plural raised portions 15A is preferably projected towards the side facing tray part 13 of heater guide 15. Raised portion 15A is preferably formed to come into contact with tray part 13 in a bent manner when heater guide 15 is fixed to attachment part 12. Raised portion 15A is, for example, arranged at three locations on each side surface side of heater guide 15 and at four locations near bottom surface 13A. That is, raised portion 15A is arranged at ten locations per one heater guide 15.

Raised portion 15A bends by contacting tray part 13 when heater guide 15 is assembled to attachment part 12. Thus, close attachment of heater guide 15 and tray part 13 is more ensured even when dimension varies in heater guide 15. In other words, heat conductivity from heater 14 to tray part 13 enhances.

Further preferred ice-making tray according to the present embodiment will be described with reference to FIG. 6. FIG. 6 is a perspective view of another ice-making tray according to the present embodiment seen from below. In this configuration, plural fins 15B extending in a direction opposite to tray part 13 is arranged at heater guide 15. Six fins 15B are arranged per heater guide 15 in FIG. 6 as an example.

The surface area for heat exchanging with cold air at the periphery of heater guide 15 increases by arranging fin 15B on heater guide 15. The heat exchange is promoted by turbulence enhancement and front edge effect, so that the temperature of heater guide 15 lowers in a short period of time. As the temperature of heater guide 15 rapidly lowers, the time for lowering the temperature of tray part 13 becomes faster, and the time for next ice-making cycle becomes shorter. The heat exchange is further promoted by arranging plural fins 15B on one heater guide 15, whereby the temperature of heater guide 15 can be more rapidly lowered.

Heater guide 15 is preferably arranged at a position substantially equally dividing the longitudinal direction of tray part 13. That is, plural heater guides 15 are preferably arranged at positions equally dividing tray part 13 in an axial direction extending along heater 14 of tray part 13. In the present embodiment, heater guide 15 are arranged at a total of three locations, i.e., the middle of heater 14, the basal side of heater 14, and the distal side of heater 14. According to such configuration, the heat transmission from heater 14 to tray part 13 becomes more uniformed without being influenced by the length of tray part 13. The heat transmission of heater 14 can be uniformed by increasing or decreasing the number of heater guides 15 according to the length of tray part 13.

Another further preferred ice-making tray according to the present embodiment will be described with reference to FIG. 7. FIG. 7 is a perspective view of another ice-making tray according to the present embodiment seen from below. In this configuration, three heater guides 15K, 15L, 15M are arranged from the basal side towards the distal side of heater 14. The width dimension thereof is such that the basal side of heater 14 is larger than the distal side of heater 14. That is, the length in the axial direction extending along heater 14 of heater guide 15K, which is a first heater guide arranged at the basal side of heater 14, is larger than the length of heater guide 15L which is a second heater guide arranged at the distal side of heater 14. The width dimension of heater guide 15M is the same as the width dimension of heater guide 15L.

The temperature does not easily rise at the basal side of heater 14 due to the presence of a caulked part of a heater line (not shown) and a lead wire terminal (not shown). Thus, the width dimension of heater guide 15K at the basal side of heater 14 is preferably made large. The heat transmission thus becomes large, and the heat transmission to tray part 13 becomes uniform without increasing the entire length of heater 14.

INDUSTRIAL APPLICABILITY

The ice-making tray according to the present invention enhances heat transmission efficiency from the heater to the metal tray part, shortens current-flowing time to the heater, and shortens the ice-making cycle, and thus can be applied as an ice-making tray for the fridge-freezer. 

1. An ice-making tray comprising: an attachment part; a metal tray part formed separately from the attachment part; a heater configured to heat the tray part; and at least one heater guide made of metal which is in contact with the heater and the tray part, the heater guide being attached to the attachment part to hold the heater, and configured to transmit heat of the heater to the tray part.
 2. The ice-making tray according to claim 1, wherein the heater guide includes a raised portion which is in contact with the tray part.
 3. The ice-making tray according to claim 1, wherein the heater guide includes a fin extending towards a side opposite to the tray part.
 4. The ice-making tray according to claim 1, wherein the ice-making tray includes a plurality of heater guides, and the plurality of heater guides are arranged at positions equally dividing the tray part in an axial direction extending along the heater.
 5. The ice-making tray according to claim 1, wherein the ice-making tray includes a first heater guide arranged at a basal side of the heater and a second heater guide arranged at a distal side of the heater, and a length of the first heater guide in an axial direction extending along the heater is larger than a length of the second heater guide in the axial direction.
 6. The ice-making tray according to claim 1, wherein a portion of the heater guide contacting the heater has a circular arc shape so as to lie along a shape of the heater. 